Document FR-A-2 669 119 describes a method of manufacturing a multiferrule out of vitreous material, the multiferrule being of the type comprising a series of parallel internal capillary channels.
Such a multiferrule is constituted by a length taken from a component of greater length, itself obtained in a fiber-drawing installation by drawing down a corresponding geometrically similar primary blank.
Document FR-A-2 674 341 describes a method of splicing together two optical fiber cables by using a glass multiferrule of the above-specified type. In that method, the stripped ends of each pair of fibers are threaded into the opposite ends of a corresponding channel, they are advanced substantially as far as the middle portion of the multiferrule, and they are locked in place inside the channel. The multiferrule is then sectioned transversely to the locked fibers to obtain two end lengths that are secured to the respective cables, and a middle length is discarded. Thereafter, splicing is performed by connecting together the two end lengths. Advantageously, a refractive index matching gel is used at the splice interface.
To facilitate sectioning the multiferrule, two grooves extending transversely to the channels are initially machined at respective ends of the middle portion, with the bottoms of the grooves opening out into the channels.
It is easier to advance the fibers in each pair of fibers along the channel receiving them when the clearance provided for the fibers in the channel is relatively large. Unfortunately, such large clearance does not make it possible to obtain accurate optical alignment of the two fibers locked in their channel. This can be compensated by taking advantage of the existing pair of transverse grooves provided specifically for sectioning the multiferrule, since they give access to both of the fibers inserted in the channel, thus making it possible to press the two fibers down against the bottom of the channel before they are locked in place, thereby ensuring that they are optically aligned.
Those various operations for connecting together two optical fiber cables are lengthy and difficult, and they do not always give rise to a satisfactory optical connection.